The investigators propose to develop a diffusion barrier to be used on blood pumps as well as other soft-tissue implants. The barrier is to be provided by a thin Titanium Nitride (TiN) coating deposited on the plastic membranes of implants. The demonstration of the diffusion barrier coating will be carried out using pulsatile blood pumps which are currently under development and designed for long-term use. The investigators describe a unique capability to apply, using a sputtering technique, biocompatible ceramics such as TiN to polymers at room temperature. The resulting coating is reported to be amorphous and tolerates flex and stretch without disruption of the barrier. The aim of the work is to alleviate what are identified as two of the most significant problems with pulsatile blood pumps, namely, diffusion of fluids from the pump system and diffusion of body fluids into the pump system.